A secondary battery device comprising a plurality of assembled batteries each including a plurality of secondary battery cells connected in series is used as a high-voltage power source. For example, a secondary battery device installed in a vehicle comprises a plurality of assembled batteries connected in series.
In some assembled batteries, a disconnector called a service disconnector or a service plug is provided in the vicinity of the central potential. By providing such a disconnector, even when some member contacts a secondary battery device including a high-pressure battery, a voltage applied to the member can be suppressed to a low level, and thereby safety of the operator who handles the secondary battery device can be improved.
A secondary battery device comprising a lithium-ion battery is known for having high impedance and high inductance with respect to high frequencies. In a secondary battery device having a large charging capacity and a large configuration, there may be cases where a parasitic capacitance is generated in the secondary battery cell when a disconnector interrupts connection between the assembled batteries. There may be cases where the parasitic capacitance and the inductance of the internal wirings form a resonant circuit, which generates a high-frequency voltage of a frequency of several MHz or higher, thereby damaging the monitoring circuit of the assembled battery.